Process for manufacture of vulcanized footwear.



PATENT-ED JUNBlQ, 1906.

. M. c. CLARK. y 'PROCESS POR MANUPAGTURB of" VULGANIZBD'PQOTWB APPILIUATION FILED ooT.zs, 19o5.

a SHEETS-SHEET i.

l WITNESSES No. 823,928. PATENTED JUNE 19, 1906.'

.l l M. O.OLARK. A PROCESS FORM-ANUPAOTURE OP` VULOANIZBD FOOTWEAR.

APPLIOATIONILED 0021.228, 1905.

3 SHEETS-SEEET 2.

No. 823,928. Y l BATENTED JUNE 19, 1906, M LARK ,t PROCESS POR MIANIIPALT n' 0F VULCANIZEDFOOTWEAR.

APPLICATION FILED 0011.2? 1 9 0 5.

SSSSSSSSSSSSS IINIrfanL .STATES DAT-ENT OFFICEo j MAURICE C; CLARK', or PROVIDENCE, .RHODE ISLAND, AssIGNoR To' MARvEL RIIBBRR COMPANY, A ACORPORATION or RHODE ISLAND.

P'RocEss-r--OR MANUFCTUREQF vULoANizED'I-ooTwEARL pecicaton of Letters Patent. .Application filed October 28, 1905. Serial No.`284,842.

Patented' June 19, 190e.'

- f-Z'o all whom it may con-,cerrar 7 Beit known that I, MAURICE C. CLARK, a citizen'of the United States, anda resident vof Providence, county' ofProvidence, and

' in molds would *bepreferable tovulcanizing State of Rhode Island,.have invented a new and vImproved Process for the Manufacture of VulcanizedA Footwear, of which the follow-y ing is a specification.

' Hf-iretofore it has been' welt known that the vulcanizing vof rubber articles of footwear them in anA ordinary vulcanizing-furnace for two reasons: in the first place, because the quality of the rubber in the mold-vulcanizedarticle is in many respects preferable to that of the 4non.mold-vulcanized' article. In the f second place, the mold performs the function of formingand marking the. exterior of the article much more 'cheaply and better than it can otherwise'be idone. Notwithstanding the above knowledge Il believe that at the present time mold vulcanized. footwear is not an article of commerce, the reason'being piane. The Doughtypatent, No.- 404,265,

' the'last and form afold that certain practical difficulties have existed which the attempts heretofore made have failed to overcome.

The object of this invention is to provide a process whereby such diflcult'ies may be overcome, and thus solve the problem of the lcommercial manufacture of mold-vulcanized footweari `Heretofore two l'methods have been attempted for solving this yproblem as follows: first,.by a mold confining the material between rigid surfaces inside and outside; second, by a mold confining the material between a rigid surfaceoutside and airpressure inside. According to the first of these systems the patent to Wren, No. 311,458, datedy January 27, 1885, confined the shoe within' an exterior mold in two parts divided substantially on the central vertical ay 28,. 1889, also? .employed a two-part o d,

the Adivision-line between whichl vwas part ofthe shoe throughoutv between the mold parts. According to the second of these systems were the patentV to Weeks, No. 233,385, October 19, 1880, and the. Doughty. patent, No.. 722,822, dated 'March- 17 1903.;l By my process .I not only obviate'the cutting of the lining above' -referred to, but may, `if desired, so dispose the rubber compoundin the article and the joint between sole and upper as to benefit the arti'- cle of footwear in other respects. I

In the accompanying drawings,Figures 1 .to 10, inclusive, represent a'completed shoe and the steps of my process of building the shoe with certain modifications. 12, and 13 represent the step of moldin'gand vulcanizing.y Fig. 14'is a vertical sectional View showing a shoe or boot made by myimproved process, the shoe or boot being of the ype commonly known as a lumbermans Under the pressure of the yside molds 'the tendency of thecompound in the upper is to fiow not merely down the edge of the sole, but over the top thereof toward the edge of the filling-sole 4.

In this specification' and claims I use the term rigid last to signify a last in which Figs. 11,

the surface next the-boot or shoe is of substantially rigid material, such as wood or metal, in contradistmction to mere air-pressure, and I use the term Irigid pressure tov signify substantially such pressure as is exertflel by such a rigid last in opposition to a m0 The shoe or boot may be'built upon the l l last as follows: Upon the last 1 is first placed. the insole 2', next the lining 3,wfith its lower edge lapping the ins' .e, as shown, next the filling-sole 4,*next the upper 5, andnext the` composed 'of outside with They are preferably partially vul- I though they may be built uponthe last in' f unv'ulcani'zed condition. This partial vulcanization may be p erformed by subjecting the coated textilef'fabric for the lining and' insole to a lower degree of heat (say 15.0) or for a shorter length of time than would ordinarily be used for theV vulcanization of the rubber compound. `The effect of this pre liminary partial .vulcanization of the lining materialis thatthe creeping on the' surface of the last `under the outside-mold pressure isl less. Moreover, the partial vulcanizatio'n has a tendency to prevent the .substantial pressure between the last and outside mold from striking or forcing the outside rubber compoundofthe upper through the textile material of the lining so as to coat the inner surface thereof with the rubber compound.

The llingsole 4 is of textile material coated on both sides With unvulcanized rubber compound. The upper 5 is a sheet of unvulcanized rubber compound which is referably slightl thicker than desired in t e iinished artic e, because the pressure of the molds has a tendency to'thin it by crowding its material toward and to some extent out at the edges of the mold parts. The up er in the completed article is preferably gra ual'lv thickened at 5EL as it approaches the sole all the way round the'shoe. For the production of this thickening dependence may be placed upon the crowding or flowing of the rubber comp; nd toward the edge above referred to or t unvulcanized sheet may be made lickerat that point before being built on the ast.

The outsole 6 may be fof ordinary con.- struction and size. If so, in building the shoe the lower edge of the upper will be lurned under the last, as shown 1n Fig. 7 at b and the outsole will be wide enough to overla it to the extreme edge of the solespace in the mold.` I prefer, however, to make the sole ofless than the full width or len th and to build as shown either in Fig. 9 or ig. 10, wherein the upper extends down into the sole-space of the mldhso that the In terial of the upper shall in the nished artic e constitute the outer edge ofthe sole. In

9 the edge of the uri-vulcanized sole' is shown 'as abutting against the side ofthe unvulcanized upper; but in Fig. 10`the u per is shown as containing an extension un er the sole and forming abeveled joint therewith. An advantage of building as shown in Figs 9 or 10 is that in the completed article the superior composition (containing a larger ercentage of real rubber and bein softer when vulcanized) of the upper eXtencFs all the way downto the bottom of the shoe and the infe- 'rior composition ofthe sole is confined to the middle portions ofthe sole, perior quality of material at theged es of the sole, where the joint occurs with t e upper and the cracking tendency of the upper is greatest and where the sole receives most blows in Wear.

In the building of the shoe above described the upper is a se parately-rolled sheet of rubber corn ound from the rubber-coated lining. This, w iile preferable, is not essential, because the sheet'constituting the upper may be rolled onto the coated lining before the lining is applied and the two applied together. ln this case preferably the coated lining will presenting a su- `at about the ball-of the foot.

be partially vulcanized, as above described, before the unvulcanized sheet constituting the upper is rolled onto it.

In building the shoe or boot having a iinin of textile material the upper may be made of low-cost rubber compound and reinforced in places where the greatest wear comes. For example, as shown in Fig. 8, the upper proper may extend between th last and a sole of less than iinal width and ingth, a separate strip 10 of superior unvulcanized rubber compound bein applied. overlapping the edge of the sole an lower part of the upper allround the shoe. Also after the building of the shoe in any of the Ways above described a vamp-piece of fine grade of rubber compound maybe applied, Figs. 1 and 2 in dotted lines,

Vforming a zone of superior rubber extending over the instep from sole to sole and from the top of lthe vamp a ortion of the distance to-` ward the toe. It tlhus covers the portions of the rubber that are most liable to wrinkle and to crack. Again, the ball of the sole may be covered by a thin iece of fine-grade rubber com ound, as indicated at 8 in Figs. 2, 3. Again, t e rear portion of the heel may also be covered by a thin piece of fine-grade rubber com ound, as indicated at 9, Fig. 2. Again, tliie superior compound of the upper forming the edge of the sole may after vulcanization extend below the lower level of the sole entirely around the' shoe, asshown in Fig. 10, so as not only to relieve the bottom of the sole from wear, but also to present a bead or series of projections of compara tivelysoft and superior rubber which will prevent the wearer from slippin After building the shoe upon ie last in the manner above described it, still containing the last, is placed Within the mold for pur poses of vulcanization, dependence being placed upon the form oi the interior of the mold to give the final form and finish to the completed article and impress upon itfany' lines or marks, such as corrugation of the sole, &c.

The molding step of the process is' as follows: Reference is made to the diagrams, Figs. 11, 12, and 13, in which A represents the inverted last (of solid or rigid material, such as wood or metal, in contradistinction to gaseous material, such as air) with shoe built upon it, as above described, at a cross-section y B and C are two side parts of the mold having motion toward and from each other. D is the solemold havin motion towardand from the two side mo ds. According to the preferable method the shoe and last are supported slightly above the vulcanizing position (about one-eiOhth of' an inch above) and the side moldsS and C are brought together, as shown in Fig. 11. Then the sole-mold is advanced so as to press the shoe and its last down into vulcanizing position, as shown in Fig. l2.

IOO

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' ceases A By this mode of operation as thej side molds are brought. together 4the presence of the space a inside their edges revents them from Vinto the side molds, is so slight-as either not to y junc'tiorrofthe side molds.

from theposition of Fig; 11 to that of Fi 12,

having any substantial c afing action'upon the' shoe, which would cause the lining-'to vcreep on the last, so as to form a fold inthe lining between the edges of the mold' at the '-Ifh'e final motion by which the last and shoe' are forced own produce any substantial cree ing of the lining on thelast 'at the sideso theishoe or if Suchcreeping occurs any resulting; fullness of the lining is substantially at the junction be-A tween the linin and the sole, where it is sub? stantially negligible It will be observed that the upper edges ofthe side molds B and.

C ar'e slig tlybeveled, so as to leavespaces b c adjacent to the edges of the sole.y The rubber forced intothese spaces by the comression of the u per (or laced; there in uilding theshoe, .as 'above escribed) forms I the thickening of the upper adjacent to the ed es of the sole, above referred to and shown in igs. 3 to B. The molds being heated to vulcanizing temperature, as soon as their heat is brought to bear upon the unvulca'nized .rubber of the upper it is almost immevenience of illustration.

diately softened to such an extent that it tends to flow away from the regions ofgreatest pressure toward the regions of less, so as to fill up any cavities provided b the mold. It .will be understood, of course, -t at Fi s. 1 1, 12, and 13 are merely diagrammatic and t e spaces a, b, and c are eXaggeratediin size for con- In lieu offemploy-l ing lthe preliminary position or :movement illustrated lin Fig. 11 the closing of the molds may, though less desirably,'be accomplished all at once, as shown in Fig. 13- -that is to say, the last and shoe A may be held m its final vulcanizing position, while the side molds B and C and sole-mold Dare all closed at once.- In this case for the revention of the formation of a fold of the lining between the side molds B C dependence must be had upon the fact that thefinal junction -of the molds B and C occurs at a line d, from which lthe curvature of the upper on each side is sufficiently abrupt, so t at the molds move only a very short distance fromthe time that they come in contact with the surface ofthe upper until they come in contact with each other, and therefore there is very little tendenc to cause the lining to creep upon. the sur ace of the last toward the line d. Such creeping `tendency isalso decreased the lining has received the preliminary artial vulcanization above referred to. Int e v ulcanized article produced by the-molds of Figs. 1 1 and 12 the upper inclusive of the preferable eirtra'thickness t V4ereof produced in the s acesl el and c willoverlap the edges of the so e, so 'that' -practically the upperextends down to so constructingv the mold vulcanize the ground, or,'-rn oth e'r words, the material of thefupper extends down toand around the. Y edges of the sole,and this I regard to-be a great advantage, because a strong smooth Joint is formed at the point of junctureof the upper and the solethat is not liable to splitor give way when lthe shoe is in'use andalso produces asole that will wear better at the edges. If the material of the upper extends ,below ythel sole, it may serve to prevent slippillgand to relieve the middle .of the sole from wear. If,

however, it be desired tohave the' upper abut I againstthe top of the sole, it may bedone by their final position they wi beas represented diagrammatically in Fig. 13, wherein' the "solel-- occipies a space e sunk. into the face vof, the D and extending laterally to the outside 1 ofthe spaces b c. i

mol

In case the heel or'out'side isi-built up of Barts that Whenin more than one layer or ta as in the case of a j 14,) the material of the 'upper will. be exlboot or a'lumbermans s oe, (shown in-Figl tended to the bottom of the sole and heel in?` elusive of any tap that the sole or heel may contain.

Having thus described my invention, f I. claim as new and desire to' secure by Letters4 1. The process of manufacturing a molded vulcanized article of footwear which consists in vulcanizing the same and during such vulcanization applyin pressure to the article in such manner that t e compound of the upper is (pressed beyond the edge of the sole bythe si e molds anddown onto the outer surface of the sole by the sole-mold.

2. The rocess of manufacturing a molded vulcanized of vulcanizin the same andfthen pressing the edge of the sole in toward the center -o f such sole. l

3. The rocess of manufacturing a molded vulcanized) article of footwear containing. a

article of footwear, which consists I054 the compoun of the upper around and over I'Io lining of textile" material which consistsin applying to the lining a coating of rubber' compound, then artiall vulcanizingV the coating, then 'app t ereto an exterior coatingofrubber compound and vulcanizing the sainewhile under substantially rigid pres- V surebetween the last and the mold.

4. .The process of manufacturing a molded i article of footwear containing a izo by pressure vulcanized .article of footwear containing a lining -of textile material which consists in partially vulcanizing the lining, applying thereto an exterior rubber.v 5 vulcanizing the compound an same While under substantialiy rigid pressure upon the .upper directed toward the-sole.v

.'7. The

vulcanize article of footwear rocessof manufacturing a molded containing a zo lining of textile material, which consists in vulcanizmdgthe same and applying substan- .tiallyri I' res/sure tocause the material to gil-dp How' tow the sole 'and then applying pressure to p 15 l the material into the sole.

and beyond the lower corner of press R. B. CAVANAGH, W. A. PAULING.

turned in on top of in vulcanizing the 

